66 RANIGANJ COAL FIELD. [CHAP. IV. § 2. 



the out-crop, but a deep shaft is now (1860) being sunk. The mine is 



the property of the Bengal Coal Company, as are also those of Chanch 



and Nuchibad, the former East, the latter West of 



Chanch and Nuchibad. 



the Kudia stream. They lie about a mile South- 

 west of Dumarkhunda. The coal, which has a thickness of about 

 10 feet, has hitherto only been worked by quarries, and by workings 

 carried in from the out-crop. It is of fair quality, and, like many other 

 seams in the Lower Damudas, e. g. Barmuri and Lalbazar, has a concre- 

 tionary structure. However this may have been produced, there can 

 be no doubt that it is due to action subsequent to the consolidation of 



the coal, and not to the " original form of the 

 " Ball coal." 



vegetation (probably drifted wood"), as suggested 



by Mr. Williams, page 74, nor to pebbles of coal washed out of 

 another bed previously deposited, as supposed by Mr. Homfray,* and 

 as was at first believed by Mr. Piddington,f who, however, on receiv- 

 ing additional specimens in better condition, immediately saw that 

 the structure was of later date than the formation of the coal4 This it 

 evidently is, for the curved surfaces of the nodules are clearly seen 

 to pass across the laminated structure parallel to the planes of stratifi- 

 cation, which is so strongly marked in all Damuda coal. The nodules, 

 indeed, have all the appearance of concretionary action, but whether 

 that is due to chemical action alone, or to heat, or to both combined, 

 it is difficult to say. 



* Second paper, page 26. 



f On the ball coal of the Buvdwan mines, Asiatic Soc. Jour. Beng., Vol. XVII., page 60. 



% Asiatic Society's Journal, Vol. XVIII., page 412, and Vol. XIX., page 76. 



Mr. Piddington attributed it to heat under pressure, and showed its analogy to columnar 

 structure. 



Mr. Williams also, in writing of the Ramghur coal, which possesses the same structure, says 

 — " These concretionaiy nodules have been erroneously supposed to be drifted boulders of coal 

 of a prior origin, which is manifestly not the case ; it is, in fact, a structure common to the coal 

 itself," &c. &c, page 28. 



